Question

3’–5’ phosphodiester linkage occurs between

• A. One DNA and other DNA strands
• B. One nucleotide with another nucleotide
• C. One nitrogenous base with pentose sugar
• D. One nucleoside with another nucleoside

Answer 1

The correct option is B One nucleotide with another nucleotide

One DNA and other DNA strands
The two strands of a DNA molecule are held together by the hydrogen bonds that bind the complementary bases pairs of the DNA double helix.
One nucleoside with another nucleoside
Nucleosides are composed of a pentose sugar and a nitrogenous base. Nucleosides do not have a phosphate group and hence cannot be linked with the help of a phosphodiester bond.
One nucleotide with another nucleotide
In the 5’-3’ strand of DNA, the adjacent nucleotides are joined with the help of 3’-5’ phosphodiester bonds that binds the 3’OH group of the previous nucleotide to the 5’ phosphate group of the next nucleotide.


Nitrogenous base with pentose sugar
Nucleosides are composed of a pentose sugar and a nitrogenous base attached to the 1’ carbon atom of the sugar by a N-glycosidic linkage.
Final answer
(C) One nucleotide with another nucleotide